1. Field of the Invention
The present invention relates to a developer storage container storing developer for electrophotographic image formation and a method of manufacturing the same.
Here, the developer storage container is a container storing developer for use in an electrophotographic image forming apparatus. It includes, for example, a process cartridge, a developer replenishment cartridge portion, which can be detachably attached to an electrophotographic image forming apparatus main body.
The electrophotographic image forming apparatus (hereinafter, referred to as the “image forming apparatus”) is one configured to form an image on a recording medium by using the electrophotographic image formation process. Examples of the image forming apparatus include an electrophotographic copying machine, an electrophotographic printer such as an LED printer or a laser beam printer, an electrophotographic facsimile apparatus, and an electrophotographic word processor.
The recording medium is a substance on which image is to be formed. Examples of the recording medium include a recording sheet and an overhead-projector (OHP) sheet.
2. Description of the Related Art
Conventionally, a process cartridge system has been known in which an electrophotographic photosensitive member and a process unit acting thereon are integrated into a cartridge together with developer as a developer storage container. The process cartridge can be attached to an image forming apparatus main body, and detached therefrom. In the process cartridge system, the maintenance of the apparatus can be performed by the user, so that it is possible to achieve an improvement in terms of operability.
The process cartridge is formed by a cleaning device (hereinafter, referred to as a cleaning unit) and a developing device (hereinafter, referred to as a developing unit). The cleaning unit has an image bearing member as the electrophotographic photosensitive member, a cleaning member for cleaning the surface of the image bearing member, etc. The developing unit has a developing roller configured to supply developer to the image bearing member, a developer storage portion for storing the developer, etc.
On the other hand, as an example of the process cartridge system, a developer replenishment system is known. In this system, a developer replenishment opening of a developer replenishment cartridge and a developer reception port of the process cartridge are connected to each other, making it possible to replenish the process cartridge with developer from the developer replenishment cartridge.
In the developer replenishment system, if new developer replenished from the developer replenishment cartridge and old developer in the developing unit are mixed with each other in an uneven state, this will result in a defective image. Therefore, the following construction is adopted for the developer replenishment type process cartridge.
The developing unit is divided into a developing portion and a developer storage portion. The developing portion and the developer storage portion are connected to each other via openings provided at both ends in the rotation axis direction of the image bearing member (hereinafter, referred to as a “longitudinal direction”). The developing portion and the developer storage portion are respectively provided with a developer conveyance member for conveying developer and a developer agitation member.
The developer conveyance member and the developer agitation member receive rotational drive from the outside via a drive transmission member, and conveys the developer in the longitudinal direction of the developer conveyance member and of the developer agitation member. By thus agitation-circulating the developer within the developing unit, new developer and old developer are uniformly mixed with each other.
The following method is known as a method of assembling this developer agitation member.
According to Japanese Patent Application Laid-Open No. 2011-158588, one end in the axial direction of the developer agitation member is retained in the vicinity of a through-hole provided in a container portion storing developer, with the one end thereof being raised, and the other end thereof is supported by an agitation member supporting portion formed on a side wall of the container portion, with a drive member being inserted via the through-hole.
However, in the method discussed in Japanese Patent Application Laid-Open 2011-158588, it is necessary to mount a drive transmission member to the developer agitation member while retaining one end of the developer agitation member in a state of being raised in the container portion storing the developer, which involves a problem in terms of workability for the assembly worker. Also in a case where the assembly is performed by an assembly robot, it is necessary for the robot to perform a similar retaining control. As a result, a complicated robot is needed.